/*
 # Copyright (c) 2009 - OpenSLX Project, Computer Center University of Freiburg
 #
 # This program is free software distributed under the GPL version 2.
 # See http://openslx.org/COPYING
 #
 # If you have any feedback please consult http://openslx.org/feedback and
 # send your suggestions, praise, or complaints to feedback@openslx.org
 #
 # General information about OpenSLX can be found at http://openslx.org/
 # --------------------------------------------------------------------------
 # pvsPrivInputSignalHandler.h:
 #  - Handle signals forwarded over a file descriptor - interface
 # --------------------------------------------------------------------------
 */

#ifndef PVSPRIVINPUTSIGNALHANDLER_H_
#define PVSPRIVINPUTSIGNALHANDLER_H_

#include <QObject>

/**
 * Handle signals.
 *
 * This class reads \c int values from a file descriptor and dispatches sends
 * Qt signals according to the \c SIG... value the integer represents.
 * The purpose of this mechanism is to integrate (asynchronous) Unix signal
 * handling into the synchronous event-driven Qt main loop. The main() function
 * is expected to open a socket pair and install handlers for all relevant signals
 * that simply write the number of the signal to that pipe.
 *
 * If allowUnauthenticatedKilling() has not been called, this class only accepts
 * signal numbers that are sent by the same process.
 */
class PVSPrivInputSignalHandler : public QObject
{
	Q_OBJECT
public:
	PVSPrivInputSignalHandler(QObject* parent = 0)
		: QObject(parent)
	{
	}

	/** If \c value is \c true, allow sending signal numbers from other processes. */
	void allowUnauthenticatedKilling(bool value)
	{
		_allowUnauthenticatedKilling = value;
	}

public slots:
	/** Connect this slot to a \c QSocketNotifier's \c activated(int) signal. */
	void signalReceived(int sigfd);

signals:
	/** SIGTERM */
	void terminate();
	/** SIGHUP */
	void reloadConfiguration();

private:
	bool _allowUnauthenticatedKilling;
};

#endif /* PVSPRIVINPUTSIGNALHANDLER_H_ */